Particle Measuring Apparatus Gas Dilution
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Solution Overview
Problem
Existing optical particle measuring apparatuses face challenges in accurately measuring particulate concentration in gas environments, particularly in semiconductor manufacturing settings, due to the risk of altering the environment's state with excessive gas sampling and miscounting high particulate concentrations.
Innovation Solution
A particle measuring apparatus that introduces a mixture of measurement target gas and filtered clean gas, using a pump to maintain a predetermined flow rate and adjust the ratio of gases to prevent environmental state changes and reduce miscounting, while using laser light to detect particles in the mixture.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a large amount of gas is sucked from the measurement environment to accurately detect particulates, then the measurement precision of particle concentration is improved, but the environment's state (atmospheric pressure, etc.) is altered
Solution Approach 1:
The patent introduces clean gas as an intermediary substance to mix with the measurement target gas. This clean gas acts as a mediator that allows the particle measuring apparatus to obtain sufficient gas for measurement without directly extracting large amounts of gas from the measurement environment, thereby preventing environmental state changes while maintaining measurement accuracy
Solution Approach 2:
The patent employs partial action by mixing a predetermined ratio of measurement target gas with clean gas. Instead of using 100% measurement target gas which would require large extraction volumes, the system uses a partial mixture (e.g., 10-90% measurement target gas mixed with 90-10% clean gas) to achieve sufficient measurement signal while minimizing environmental impact
2Quantity of substance
If a high concentration of particulates is present in the measurement atmosphere, then the particle concentration is high, but the apparatus may count multiple particulates as one, reducing measurement precision
Solution Approach 1:
The patent applies partial action by mixing measurement target gas with clean gas in predetermined ratios to reduce the particulate concentration in the measurement mixture. This dilution effect prevents multiple particles from entering the measurement region simultaneously, eliminating the miscounting problem while still allowing accurate measurement of the original high concentration through proper ratio control
Solution Approach 2:
The patent changes the concentration parameter of the measurement gas mixture by mixing with clean gas. This parameter adjustment reduces the particle density in the measurement region, preventing particle aggregation effects and multiple particle miscounting, while the system maintains the ability to calculate original concentrations through the known mixing ratios
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables accurate measurement of particulate concentration without altering the environment's state and reduces miscounting of particles, allowing for precise monitoring in semiconductor manufacturing processes.
Implementation Method 1
detecting scattered light generated when the sucked atmosphere is irradiated with laser light
Data Source
AI summary
A particle measuring apparatus according to an embodiment includes a first supply part that introduces first gas. A second supply part introduces second gas having been filtered. A light source irradiates mixture gas including the first gas and the second gas with light. A light detector detects reflected light from the mixture gas and measures number of particles contained in the mixture gas. A pump sucks the mixture gas.